China launches its first aircraft carrier into formal service at a time tense terrirorial dispute with Japan.

DALIAN, LIAONING PROVINCE, CHINA (SEPTEMBER 25, 2012) (CCTV) - China put its first aircraft carrier into formal service on Tuesday (September 25) amid a tense maritime dispute with Japan in a show of force that could worry its neighbours.

China's Ministry of Defence said the newly named Liaoning aircraft carrier would "raise the overall operational strength of the Chinese navy" and help Beijing to "effectively protect national sovereignty, security and development interests".

In fact, the aircraft carrier, refitted from a ship bought from Ukraine, will have a limited role, mostly for training and testing ahead of the possible launch of China's first domestically built carriers after 2015, analysts say.

China cast the formal handing over of the carrier to its navy -- attended by President Hu Jintao and Premier Wen Jiabao -- as a triumphant show of national strength at a time of tensions with Japan over islands claimed by both sides.

Wen said that the commissioning of China's first aircraft carrier has "important and profound meaning" for the modernisation of the country's navy, national defense and overall strength, Xinhua news agency cited the premier as saying.

Sino-Japanese relations deteriorated sharply this month after Japan bought the East China Sea islands, called Senkaku in Japan and Diaoyu in China, from their private owner, sparking anti-Japan protests across China.

In a sign of the tensions, China has postponed a ceremony marking the 40th anniversary of the resumption of diplomatic ties with Japan. But an official at the Japan-China Economic Association said Toyota Motor Corp Chairman Fujio Cho and Hiromasa Yonekura, chairman of Japanese business lobby Keidanren, and other representatives of Japan-China friendship groups would attend an event on Thursday in Beijing.

The risks of military confrontation are scant, but political tensions between Asia's two biggest economies could fester and worries persist about an unintended incident at sea.